Intercropping for forage production

Intercropping offers several advantages in relation to cultivation and soil fertility. At the same time, a healthier feed can be produced when the crops are mixed in the field, and it is possible to ensure a higher protein- or fat content in feed that is produced in intercropping systems.

Milk producers often mix different crops in the feed and will be able to save costs on e.g. cleaning, drying, and mixing feed as well as for transport of feed, if they plan in advance.

What is intercropping?

Intercropping is the simultaneous cultivation of more than two crop species in the same field in a system which is typically more robust than monocultural production. Fields for growing only one type of crop at a time have become larger in recent years which means that the soil type often varies across the individual field. In some places, the soil may be sandy at one end of the field and rich in humus and clay at the other end. 

The variation within these big fields makes it more challenging to achieve a stable yield from the whole field in a monocultural system, as crops typically perform best under certain growing conditions. An intercropping system typically adapts better to soil conditions, as the crop species that perform well on sandy soil will dominate the sandy areas of the field, whereas other species will grow well in other areas of the field.

The yield stability may be greater in intercropping systems than in monocultural systems because the mix of crops typically includes species or varieties with specific levels of tolerance to for instance drought or overwatering. Different types of crops also have roots that vary in length which ensures uptake of water and nutrients from different depths of the soil.

Mixing many species with different characteristics, for instance different root lengths, enhances soil fertility by ensuring positive carbon sequestration in the soil and humus formation. In the long run, better soil fertility will ensure even better yield stability despite more extreme weather. Finally, the diversity in intercropping systems ensures greater resistance to disease and pest attacks.

The mix of crops must suit the needs of the farm

There is no specific recipe for a mix of crops that suits all farms. Which crops to mix depends on the needs of the farm when it comes to feed requirements and soil type. It is important to consider the desired milk yield and thus make sure that the protein and fat content as well as digestibility of the feed is adapted to meet the needs.

Field planning is crucial before starting up an intercropping system for forage production. It may be a good idea to talk to an advisor to do the field planning well and brainstorm on which species to mix according to soil type and feed requirements.

It may also be an advantage to cultivate a herb meadow after a main crop in an intercropping system. A greater content of different herbs and grasses in a clover meadow will ensure a healthier feed which contains more different nutrients and minerals. At the same time, it is possible to achieve a more even yield curve over the season from the herb meadow due to greater diversity in the crop of different species which have different growth curves and times of peak production. The herbs, grasses and clovers which have extra deep roots will also be able to ensure some production even in dry conditions.

Uniform arable land is difficult to achieve because the crops that suit the different qualities will be dominant in the areas where the soil suits them. The climate of the individual year will also have a major influence on which species will dominate during the growing season. Of course, this must be accepted in relation to the future field and feed plan.